Rob Crilly is Pakistan correspondent of The Daily Telegraph and The Sunday Telegraph. Before that he spent five years writing about Africa for The Times, The Irish Times, The Daily Mail, The Scotsman and The Christian Science Monitor from his base in Nairobi.

Hostage tragedy: Nigeria is in danger of turning into a blood-soaked African Pakistan

Africa's religious divide: the arid deserts of the north and the green tropical south

Africa's religious divide is visible from space. Satellite images show the browns and burnt yellows of the arid north giving way to tropical greens as the view moves from north to south.

The coloured frontier slices through Nigeria in the west through Sudan, reaching the Indian Ocean in Kenya. To the north lie Muslim lands, to the south the religion is predominantly Christian.

I travelled across that line in 2001, shortly after 9/11, driving from the Nigerian capital Abuja to the historic city of Sokoto, scene of Thursday's failed attempt to rescue Chris McManus and Franco Lamolinara.

Then, I was welcomed with astounding hospitality. It may have been Ramadan and a time of fasting for the locals, but a hungry traveller could find flat bread and hard boiled eggs at any time of day. And there was even beer at dinner time. Time and again I was told that the largely Sufi Muslims of northern Nigeria shared my horror at the events in the US two months earlier. The only blip was a photo I spotted of Osama bin Laden pasted to a bus, which my hosts explained away as a remnant of a time when no-one imagined the true horror of al-Qaeda.

Things have changed since then. The religious divide has become a faultline.

Religious riots have claimed hundreds of lives in Nigeria in cities such as Jos, where murderous gangs in 2010 sought out Christians they believed enjoyed social and economic advantages.

Samantha Lewthwaite, widow of one of London's 7/7 bomber, is thought to be on the run in Kenya having joined up with members of a Somali-linked terror cell.

In the past year, intelligence officials believe al-Qaeda has been badly damaged in its Pakistani boltholes. Bin Laden was killed on May 2, and senior commanders have been targeted by an intense barrage of drone strikes. As a result, they have begun a migration to safer climes – Yemen, Somalia and North Africa, among them.

There they will find many of the factors that made Pakistan a haven for a decade: governments that struggle to impose their will on remote corners of their territory; long, porous borders; and a patchwork of local disputes that can be manipulated and fitted into an anti-Western narrative that justifies terror attacks.

At the same time, vast stockpiles of weapons have simply disappeared from Libya since the downfall of Colonel Gaddafi. In addition, Tuareg fighters who once pledged allegiance to the Libyan leader have returned to Mali, reigniting a simmering war.

An influx of al-Qaeda leaders and missing crates of anti-aircraft missiles is a recipe for disaster. The first casualty could be the centuries-old trading sultanate of Sokoto. Reports suggest Boko Haram has its sights on Sultan of Sokoto Sa'ad Abubakar III, angry at how much power is invested in a single individual.

Nigeria is still a long way from the bloody insurgency that has brought so much pain to Pakistan. But it would be a tragedy for its religious differences – and the peaceful, moderate population in the north – to be exploited by foreign Islamofascists from outside.

Imran Khan, Pakistan's cricketer-turned-politician, tells the story of how he once took his father-in-law Jimmy Goldsmith to Waziristan in the remote tribal areas to dine on succulent roast lamb. Such a visit by a Westerner is impossible now. I hope Sokoto does not go the same way.